(1) Field of the Invention
This invention relates to a communication apparatus, communication system, and method for integrating speech and data and, more particularly, to a communication apparatus for communicating by integrating speech and data, communication system for communicating by integrating speech and data, and method for integrating speech and data for communicating by integrating and controlling speech and data.
(2) Description of the Related Art
In recent years, in addition to conventional centralized telephone switching service, the use of high-speed transmission via distributed LAN for local communication is increasing. As a result, intranet communication is widely performed. Conventionally, installations for such an in-house PBX network and intranet have been constructed separately from each other because of their difference in protocol. Conventionally, a public telephone trunk network and internet trunk network have also been installed separately from each other.
A telephone network and data network are installed separately from each other in this way, resulting in low installation efficiency. Furthermore, lines are used separately, resulting in low efficiency in the use of lines.
To take an example of conventional techniques, Japanese Patent Laid-Open Publication No.Hei 11-252249 discloses a switching system for exchanging frames, being speech made into MAC frames, and LAN data in order to realize communication in which telephone speech and data are integrated.
In recent years, on the other hand, Internet telephone for performing speech communication via Internet has appeared. It uses voice over IP (VoIP) technique in order to realize speech communication on an IP network.
The above conventional technique, however, needs to develop a new switching system which accommodates trunk lines for telephones, data terminals, public networks, etc. Therefore, it is not easy to change the installations.
Communication networks are built with telephone networks as their centers. Therefore, what is important is not to simply add new systems, but to minimize the increase of installations by the use of the existing network systems in order to provide new services.
The conventional Internet telephone must be connected to a dedicated server in order to speak. Moreover, the inability to ensure bandwidth for the conventional Internet telephone causes delay or lack of speech, resulting in poor speech communication quality.